gRPC Server Backward Compatibility Issues and Workarounds Manageent
Introduction
This document lists the workarounds implemented on gRPC servers for record and reference when users need to enable a certain workaround.
Workaround List
Cronet Compression
Workaround ID: WORKAROUND_ID_CRONET_COMPRESSION
Date added: May 06, 2017
Status: Implemented in C core and C++
Issue: Before version v1.3.0-dev, gRPC iOS client's Cronet transport did not implement compression. However the clients still claim to support compression. As a result, a client fails to parse received message when the message is compressed. The problem above was resolved in gRPC v1.3.0-dev. For backward compatibility, a server must forcingly disable compression for gRPC clients of version lower than or equal to v1.3.0-dev.
Workaround Description: Implemented as a server channel filter in C core. The filter identifies the version of peer client with incoming user-agent header of each call. If the client's gRPC version is lower that or equal to v1.3.x, a flag GRPC_WRITE_NO_COMPRESS is marked for all send_message ops which prevents compression of the messages to be sent out.